Google Classroom Userstyle

This userstyle which can be installed through the Stylus extension (also available for Firefox) applies several useful tweaks to Google Classroom.

Google Classroom Tweaks Userstyle

It moves the +Create button in the Classwork tab up and fixes its position so it does not scroll away.

It outlines the boxes on rubrics for easier visibility.

In the grading view, it reduces the height of the top panel to give you more vertical space to view your students' assignments. It also widens the right panel to make it more usable.